A Numerical Approach to Optimize the Design of a Pintle Injector for LOX/GCH4 Liquid-Propellant Rocket Engine

Abstract

This study presents an optimal design approach of a pintle injector for a deep throttlable liquid-propellant rocket engine (LPRE). Even though the pintle injector is used in rocket engines, it has become more important since reusable launch vehicles (RLVs) recently became a trend due to their economic and environmental benefits. However, since many variables must be determined to design a pintle injector, optimizing the pintle injector design is complicated. For this, we design a pintle injector to optimize the performance parameters; the spray angle, vaporization distance, and Sauter mean diameter (SMD). To confirm the approach, we design a pintle injector using an optimization method based on convex quadratic programming (CQP) for a 1000 N thrust and a throttle ability of 5 to 1 LPRE with liquid oxygen and gaseous methane. Then, we verify the performance using a numerical simulation. Through this work, we check the effectiveness of the optimization method for a pintle injector design.

Transient Characteristics of Fluidic Pintle Nozzle in a Solid Rocket Motor

“…A typical mechanical type is the pintle motor [3,4], which controls the thrust by changing the effective gas flow area (the throat formed by the nozzle wall and pintle) through the movement of the pintle. Research on the pintle motor began in 1968, and the large motor (267 kg of propellant mass) achieved a thrust control of 567-3900 kg [5], but ignition and sustained combustion were not smooth.…”